Tuesday evening's UEFA Champions League match between FC Basel and FC Schalke 04 was temporarily halted after protesters came rappelling down onto St. Jakob-Park, sending the crowd into an uproar.

ESPN.co.uk tweeted about the situation and captured this image.

The protesters were members of Greenpeace, an independent organization that works to raise awareness on environmental issues. Rappelling down from the roof of the stadium, they carried a banner that read "Gazprom, Don't Foul the Arctic" and the hashtag "FreeTheArctic30."

The Arctic 30 refers to the activists Russian authorities arrested in September, who were protesting Gazprom's drilling in the ocean. Officers allegedly beat and kicked the activists while holding them at gunpoint before they were held prisoner at embassies throughout the country, according to Jonathan Brown of The Independent.

The banner also promoted a redirect to Greenpeace's official website, which pleas for support in protesting drilling in the Arctic and asks for help in releasing the protesters held captive. Bloomberg's Henry Meyer reported on Monday that the Russian government was planning on charging them with piracy. If convicted, the protesters could serve up to 15 years in jail.

Greenpeace likely chose Tuesday's match for their high-profile protest because of Schalke's sponsorship agreement with the natural gas extractor. Gazprom has been a main sponsor for the Bundesliga side, who finished fourth in the table last season.

The match, held in Swiss side Basel's home field, was delayed for just a short time as stadium officials worked to subdue the protesters and quiet the ruckus. Both sides came into Tuesday's contest with 1-0 records in Group E, looking to take an early lead in the table.

Still, according to Associated Press sports writer Graham Dunbar, the protest could have immediate and severe consequences for the Swiss side:

Basel were coming off an upset of Premier League side Chelsea in their first match. Schalke scored a 3-0 victory over Steaua Bucuresti, who are considered the least likely to advance past the four-team group stage.

Schalke currently lead the match 1-0 in the 54th minute at the time of publication.